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Chapter 7. Stand-alone Servers

John H. Terpstra

Samba Team

Table of Contents

Features and Benefits
Background
Example Configuration
Reference Documentation Server
Central Print Serving
Common Errors

Stand-alone Servers are independent of Domain Controllers on the network. They are not Domain Members and function more like workgroup servers. In many cases a Stand-alone Server is configured with a minimum of security control with the intent that all data served will be readily accessible to all users.

Features and Benefits

Stand-alone Servers can be as secure or as insecure as needs dictate. They can have simple or complex configurations. Above all, despite the hoopla about Domain Security they remain a common installation.

If all that is needed is a server for read-only files, or for printers alone, it may not make sense to effect a complex installation. For example: A drafting office needs to store old drawings and reference standards. No-one can write files to the server as it is legislatively important that all documents remain unaltered. A share mode read-only Stand-alone Server is an ideal solution.

Another situation that warrants simplicity is an office that has many printers that are queued off a single central server. Everyone needs to be able to print to the printers, there is no need to effect any access controls and no files will be served from the print server. Again, a share mode Stand-alone Server makes a great solution.

Background

The term Stand-alone Server means that it will provide local authentication and access control for all resources that are available from it. In general this means that there will be a local user database. In more technical terms, it means resources on the machine will be made available in either SHARE mode or in USER mode.

No special action is needed other than to create user accounts. Stand-alone servers do not provide network logon services. This means that machines that use this server do not perform a domain logon to it. Whatever logon facility the workstations are subject to is independent of this machine. It is, however, necessary to accommodate any network user so the logon name they use will be translated (mapped) locally on the Stand-alone Server to a locally known user name. There are several ways this can be done.

Samba tends to blur the distinction a little in respect of what is a Stand-alone Server. This is because the authentication database may be local or on a remote server, even if from the SMB protocol perspective the Samba server is not a member of a domain security context.

Through the use of Pluggable Authentication Modules (PAM) and the name service switcher (NSSWITCH), which maintains the UNIX-user database) the source of authentication may reside on another server. We would be inclined to call this the authentication server. This means that the Samba server may use the local UNIX/Linux system password database (/etc/passwd or /etc/shadow), may use a local smbpasswd file, or may use an LDAP backend, or even via PAM and Winbind another CIFS/SMB server for authentication.

Example Configuration

The examples, Reference Documentation Server, and Central Print Serving, are designed to inspire simplicity. It is too easy to attempt a high level of creativity and to introduce too much complexity in server and network design.

Reference Documentation Server

Configuration of a read-only data server that everyone can access is very simple. Following example is the smb.conf file that will do this. Assume that all the reference documents are stored in the directory /export, and the documents are owned by a user other than nobody. No home directories are shared, and there are no users in the /etc/passwd UNIX system database. This is a simple system to administer.

Example 7.1. smb.conf for Reference Documentation Server

# Global parameters
[global]
workgroup = MIDEARTH
netbios name = GANDALF
security = SHARE
passdb backend = guest
wins server = 192.168.1.1
[data]
comment = Data
path = /export
guest only = Yes

In the example above, the machine name is set to GANDALF, the workgroup is set to the name of the local workgroup (MIDEARTH) so the machine will appear together with systems with which users are familiar. The only password backend required is the “guest” backend to allow default unprivileged account names to be used. As there is a WINS server on this network, we of obviously make use of it.

Central Print Serving

Configuration of a simple print server is easy if you have all the right tools on your system.

Assumptions:

  1. The print server must require no administration.

  2. The print spooling and processing system on our print server will be CUPS. (Please refer to CUPS Printing Support for more information).

  3. The print server will service only network printers. The network administrator will correctly configure the CUPS environment to support the printers.

  4. All workstations will use only postscript drivers. The printer driver of choice is the one shipped with the Windows OS for the Apple Color LaserWriter.

In this example our print server will spool all incoming print jobs to /var/spool/samba until the job is ready to be submitted by Samba to the CUPS print processor. Since all incoming connections will be as the anonymous (guest) user, two things will be required:

Enabling Anonymous Printing

  • The UNIX/Linux system must have a guest account. The default for this is usually the account nobody. To find the correct name to use for your version of Samba, do the following:

    $ testparm -s -v | grep "guest account"
    

    Make sure that this account exists in your system password database (/etc/passwd).

  • The directory into which Samba will spool the file must have write access for the guest account. The following commands will ensure that this directory is available for use:

    root# mkdir /var/spool/samba
    root# chown nobody.nobody /var/spool/samba
    root# chmod a+rwt /var/spool/samba
    

The contents of the smb.conf file is shown in the next example.

Example 7.2. smb.conf for Anonymous Printing

# Global parameters
[global]
workgroup = MIDEARTH
netbios name = GANDALF
security = SHARE
passdb backend = guest
printing = cups
printcap name = cups
[printers]
comment = All Printers
path = /var/spool/samba
printer admin = root
guest ok = Yes
printable = Yes
use client driver = Yes
browseable = No

Note

On CUPS-enabled systems there is a facility to pass raw data directly to the printer without intermediate processing via CUPS print filters. Where use of this mode of operation is desired, it is necessary to configure a raw printing device. It is also necessary to enable the raw mime handler in the /etc/mime.conv and /etc/mime.types files. Refer to Explicitly Enable “raw” Printing for application/octet-stream.

Common Errors

The greatest mistake so often made is to make a network configuration too complex. It pays to use the simplest solution that will meet the needs of the moment.